Yakama Nation Pronghorn - WDFW Report

[Cougeyes]

For those interested in the status of the pronghorn reintroduced on the Yakama reservation. PDF attached, can also be found here: https://wdfw.wa.gov/publications/02288

[andersonjk4]

Very interesting. Thanks for sharing.

Here is the population and conclusion sections for those interested:

"Pronghorn Population
The 250 pronghorn observed during the survey represent a minimum population count for
south-central Washington. This population is considered a closed population with no known
movements across the Columbia River to the south where populations reside in Oregon, or east to populations reintroduced in North-central WA by the Collvile Tribe. The 2021 count is comparable to the 2019 count (248 pronghorn). Shortly after the Feb 2019 survey, heavy snowfall and cold temperatures in February and March 2019 resulted in a severe mortality event especially amongst the 50 newly introduced pronghorn released in January 2019. Over 80% of these newly relocated animals were believed to have perished following the survey. Therefore, the relatively stable counts between 2019 and 2021 despite this known mortality event between counts indicate this small population is moderately resilient and continues to grow and sustain itself through natural recruitment, to an extent. No further reintroductions are currently planned by the Yakama Tribe. This count is a minimum and it is likely that more animals exist in this landscape. Detection of small groups can be challenging during flights and this survey was conducted past the optimal timeframe as wintering groups were breaking up. Efforts should continue to attempt to conduct flights earlier in winter (January). In addition, pronghorn may have been in areas missed during this year’s survey in the eastern transects left incomplete, or outside our survey boundary. Reports of up to 40 animals west of Hwy 97 on the Yakama Reservation were received in the spring following the survey but never confirmed. This area should be considered for future flight survey expansion or more in-depth ground surveys.

CONCLUSION
Our minimum south-central population of pronghorn was 250, indicating effectively no
change from 2019 despite a known winter mortality event from which the population has
rebounded. The population appears to be growing and maintaining itself naturally but is still small and considered sensitive to adult mortality including roadkill, harsh winter conditions, and changing habitat and land use. Biennial survey flights have been a positive cooperative undertaking and should be a continued priority for the WDFW, Yakama Tribe, and SCI partners. The Yakama Nation and WDFW are currently both developing plans regarding future management for this herd."

[PKC]

Very interesting!  Thanks for posting that.

[Farmer72]

In another 20 years it might be a new OIL tag that very few will be able to draw in their lifetime.

[boneaddict]

I see them every once in awhile.  Still there for sure, but not busting at the seems.   I’d imagine coyotes are hell on fawns.   Lots of coyotes.

[Sandberm]

Very interesting. Thanks for sharing.

Here is the population and conclusion sections for those interested:

"Pronghorn Population
The 250 pronghorn observed during the survey represent a minimum population count for
south-central Washington. This population is considered a closed population with no known
movements across the Columbia River to the south where populations reside in Oregon, or east to populations reintroduced in North-central WA by the Collvile Tribe. The 2021 count is comparable to the 2019 count (248 pronghorn). Shortly after the Feb 2019 survey, heavy snowfall and cold temperatures in February and March 2019 resulted in a severe mortality event especially amongst the 50 newly introduced pronghorn released in January 2019. Over 80% of these newly relocated animals were believed to have perished following the survey. Therefore, the relatively stable counts between 2019 and 2021 despite this known mortality event between counts indicate this small population is moderately resilient and continues to grow and sustain itself through natural recruitment, to an extent. No further reintroductions are currently planned by the Yakama Tribe. This count is a minimum and it is likely that more animals exist in this landscape. Detection of small groups can be challenging during flights and this survey was conducted past the optimal timeframe as wintering groups were breaking up. Efforts should continue to attempt to conduct flights earlier in winter (January). In addition, pronghorn may have been in areas missed during this year’s survey in the eastern transects left incomplete, or outside our survey boundary. Reports of up to 40 animals west of Hwy 97 on the Yakama Reservation were received in the spring following the survey but never confirmed. This area should be considered for future flight survey expansion or more in-depth ground surveys.

CONCLUSION
Our minimum south-central population of pronghorn was 250, indicating effectively no
change from 2019 despite a known winter mortality event from which the population has
rebounded. The population appears to be growing and maintaining itself naturally but is still small and considered sensitive to adult mortality including roadkill, harsh winter conditions, and changing habitat and land use. Biennial survey flights have been a positive cooperative undertaking and should be a continued priority for the WDFW, Yakama Tribe, and SCI partners. The Yakama Nation and WDFW are currently both developing plans regarding future management for this herd."

At the time i wondered how they fared in that harsh weather conditions. No so good it sounds like but they have rebounded nicely.

Thanks for sharing!

[Karl Blanchard]

I see them every once in awhile.  Still there for sure, but not busting at the seems.   I’d imagine coyotes are hell on fawns.   Lots of coyotes.

coyotes are nasty on antelope fawn mortality for sure! I also wonder about the over population of feral horses on the Yakama rez being a detrimental thing to antelope? What kind of competition are the horses for habitat use?  Yakama's need to do some chopper gunnin of coyotes and horses 

[D-Rock425]

I saw two of i90 west of spokane last summer

[Slenk]

There is a small herd that hang out east of Ritzville pretty close to the town we see them quit often

[Platensek-po]

I see them every once in awhile.  Still there for sure, but not busting at the seems.   I’d imagine coyotes are hell on fawns.   Lots of coyotes.

coyotes are nasty on antelope fawn mortality for sure! I also wonder about the over population of feral horses on the Yakama rez being a detrimental thing to antelope? What kind of competition are the horses for habitat use?  Yakama's need to do some chopper gunnin of coyotes and horses 

Are feral horses considered invasive non classified wildlife??? Curious

[Stein]

I would guess habitat in general is a far more important factor than horses and cows but every piece of pressure is cumulative.

[Karl Blanchard]

I would guess habitat in general is a far more important factor than horses and cows but every piece of pressure is cumulative.

Yakama nation estimates carrying capacity at 3k horses and there is north of 15k. Thats the current habitat issue.

[Karl Blanchard]

I see them every once in awhile.  Still there for sure, but not busting at the seems.   I’d imagine coyotes are hell on fawns.   Lots of coyotes.

coyotes are nasty on antelope fawn mortality for sure! I also wonder about the over population of feral horses on the Yakama rez being a detrimental thing to antelope? What kind of competition are the horses for habitat use?  Yakama's need to do some chopper gunnin of coyotes and horses 

Are feral horses considered invasive non classified wildlife??? Curious

the "wild horse" or more accurately feral horse thing is a big ol can of worms to be opened.

[Mtnwalker]

I would guess habitat in general is a far more important factor than horses and cows but every piece of pressure is cumulative.

There are sections out there that look like a moonscape due to those horses

[Ironhead]

Coyotes are also hard on adults if the conditions are right. Out near Mansfield a few years back there was a significant snow fall that got rained on then crusted over. The Coyotes could run on top but the Antelope couldn't. They took a pretty good hit that year.